A conventional data storage system typically includes (i) a storage processor and (ii) a set of disk drives, e.g., a disk array enclosure (DAE) containing one or more disk drives. During operation, the storage processor carries out data storage operations on behalf of one or more external host devices. For example, when the storage processor receives a request from an external host device to write host data, the storage processor stores the host data on the set of disk drives (perhaps in accordance with a RAID level). Similarly, when the storage processor receives a request from an external host device to read host data, the storage processor loads the host data from the set of disk drives (unless the host data is already available in cache memory from an earlier operation) and provides the host data to the requesting host device.
Some data storage systems separate disk interfacing circuitry from other storage processor circuitry. For example, in one conventional data storage system having multiple storage processors, each storage processor communicates with (i) a first bank of DAEs through a first disk interface module, and (ii) a second bank of DAEs through a second disk interface module. Each disk interface module is configured to carry out a specific standardized storage device protocol such as SCSI (the Small Computer System Interface) or SATA (Serial ATA). In the event of a disk interface module failure, only the failed disk interface module needs to be replaced. That is, the storage processor circuitry can remain in place and can continue to carry out data storage operations through the non-failed disk interface module.
Some conventional data storage systems are further equipped with encryption keys to encrypt and decrypt communications exchanged between the data storage systems and the external host devices. This provides a level of security for communications along the routes between the data storage systems and the external host devices which, in some cases, may be over public networks.
Furthermore, host data can be encrypted prior to storage on the disk drives. For example, a host device can send encrypted host data (e.g., an encrypted file, an encrypted database transaction, etc.) to the data storage system, and the storage processors can then store the encrypted host data on the disk drives in the same manner as non-encrypted host data.